Methods of Automatically Answering a Phone Call with a Mobile Terminal and Associated Mobile Terminals

1. A method of automatically answering a phone call with a mobile terminal, the method comprising: obtaining a coordinate pair of each part of an ear of an authorized user relative to reference coordinate axes and storing the coordinate pair as a sample coordinate pair; obtaining, at every predetermined period of time, a pressure value and a coordinate pair of each contact point between an ear of a current user and a touch screen of the mobile terminal when there is an incoming phone call, each pressure value comprising a pressure magnitude and pressure area; determining whether a number of the contact points as detected is smaller than a first predetermined value; if so determined, prompting the current user to re-contact the ear with the touch screen; and if not so determined, obtaining an outer contour of the ear of the current user based on the pressure values and the coordinate pairs; selecting among the outer contour three parts of the ear to establish reference coordinate axes; calculating a relative coordinate pair of each contact point corresponding to each part of the ear in the outer contour with respect to the reference coordinate axes; comparing the relative coordinate pairs against the sample coordinate pairs of each part of the ear of the authorized user relative to the reference coordinate axes; and unlocking and automatically answering the phone call when the relative coordinate pairs match the sample coordinate pairs.

2. The method according to claim 1 , wherein the comparing the relative coordinates with the sample coordinate pair comprises: computing and recording, between each relative coordinate pair and a corresponding sample coordinate pair, an absolute difference between abscissas as a first absolute value, and an absolute difference between ordinates as a second absolute value, the relative coordinate pair and the corresponding sample coordinate pair both corresponding to a same part of the ear; obtaining a number of the relative coordinate pairs each of which the first absolute value lies within a first predetermined range and the second absolute value lies within a second predetermined range; and determining the relative coordinates match the stored sample coordinates when the number of the relative coordinate pairs is greater than or equal to a second predetermined value.

3. The method according to claim 1 , wherein the selecting among the outer contour the three parts of the ear to establish the reference coordinate axes comprises: selecting from the outer contour a crus of helix, tragus, and antitragus of the ear to establish the reference coordinate axes.

4. A method of automatically answering a phone call with a mobile terminal, the method comprising: obtaining, at every predetermined period of time, a pressure value and coordinates of each contact point between an ear of a current user and a touch screen of the mobile terminal when there is an incoming phone call, each pressure value comprising a pressure magnitude and pressure area; obtaining an outer contour of the ear of the current user based on the pressure values and the coordinates; selecting, among the outer contour three parts of the ear to establish reference coordinate axes; calculating a relative coordinate pair of each contact point corresponding to each part of the ear in the outer contour with respect to the reference coordinate axes; comparing the relative coordinates against pre-stored sample coordinate pairs, of each part of an ear of an authorized user relative to the reference coordinate axes; and unlocking and automatically answering the phone call when the relative coordinate pairs match the pre-stored sample coordinate pairs.

5. The method according to claim 4 , further comprising, after the obtaining, at every predetermined period of time, the pressure value and coordinates of each contact point: determining whether a number of the contact points as detected is smaller than a first predetermined value; if so determined, prompting the current user to recontact the ear with the touch screen; and if not so determined, obtaining an outer contour of the ear of the current user based on the pressure values and coordinates.

6. The method according to claim 5 , wherein the comparing the relative coordinates with the pre-stored sample coordinate pairs comprises: computing an absolute difference of abscissas and an absolute difference of ordinates between each relative coordinate pair and a pre-stored sample coordinate pair, the relative coordinate pair and the pre-stored sample coordinate pair both corresponding to a same part of the ear, the absolute difference between the abscissas being recorded as a first absolute value and the absolute difference between the ordinates being recorded as a second absolute value; obtaining a number of the relative coordinate pairs each of which the first absolute value lies within a first predetermined range and the second absolute value lies within a second predetermined range; and determining whether the relative coordinates match the pre-stored sample coordinates when the number is greater than or equal to a second predetermined value.

7. The method according to claim 4 , wherein the selecting among the outer contour the three parts of the ear to establish the reference coordinate axes comprises: selecting from the outer contour a crus of helix, tragus, and antitragus of the ear to establish the reference coordinate axes.

8. The method according to claim 4 , further comprising, before obtaining at every predetermined period of time the pressure value and coordinates of each contact point: obtaining coordinate pairs of each part of an ear of an authorized user relative to reference coordinate axes and storing the coordinates as sample coordinate pairs.

9. A mobile terminal for automatically answering a phone call, the mobile terminal comprising a touch screen and a Digital Processing Unit (DSP), wherein the touch screen is configured to obtain, at every predetermined period of time, a pressure value and coordinate pairs of each contact point between an ear of a current user and the touch screen when there is an incoming phone call, each pressure value comprising a pressure magnitude and pressure area; and the DSP unit is configured to: obtain an outer contour of the ear of the current user based on the pressure values and coordinate pairs; select, among the outer contour of the ear, parts of the ear to establish reference coordinate axes; compute relative coordinate pairs, of the contact points, each corresponding to one of the parts of the ear in the outer contour of the ear with respect to the reference coordinate axes; compare the relative coordinate pairs against pre-stored sample coordinate pairs of each part of an ear of an authorized user relative to reference coordinate axes; and unlock the mobile terminal and automatically answer the phone call when determining the relative coordinate pairs match the pre-stored sample coordinate pairs.

10. The mobile terminal according to claim 9 , wherein the DSP unit is further configured to: determine whether a number of the contact points as detected is smaller than a first predetermined value; and if so determined, prompt the current user to recontact the ear with the touch screen, and if not so determined, perform the operation of obtaining the outer contour of the ear of the current user based on the pressure values and the coordinates.

11. The mobile terminal according to claim 10 , wherein the DSP unit is further configured to: compute and record an absolute difference between an abscissa and an ordinate of each relative coordinate pair and an abscissa and an ordinate of a sample coordinate pair, the relative coordinate pair and the sample coordinate pair both corresponding to a same part of the ear, the absolute difference between the abscissas being recorded as a first absolute value and the absolute difference between the ordinates being recorded as a second absolute value; obtain a number of the relative coordinate pairs each of which the first absolute value lies within a first predetermined range and the second absolute value lies within a second predetermined range; and determine whether the number of relative coordinate pairs match the pre-stored sample coordinate pairs is greater than or equal to a second predetermined value.

12. The mobile terminal according to claim 9 , wherein the DSP unit is further configured to select from the outer contour a crus of helix, tragus, and antitragus of the ear to establish the reference coordinate axes.

13. The mobile terminal according to claim 9 , further comprising an application processor configured to: package the sample coordinates into firmware that is recognizable by the DSP unit; control the DSP unit to switch from operating mode to download mode to download the firmware to the DSP unit; and continue to control the DSP unit to switch from the download mode back to the operating mode.

14. The method according to claim 1 , wherein a magnitude of the first predetermined value is set depending on application, comprising: if a fast matching speed is required, a relatively small first predetermined value is configured; and if a high matching accuracy is required, a relatively great first predetermined value is configured.

15. The method according to claim 2 , wherein each part of the ear of the authorized user corresponds to a plurality of sample coordinate pairs, and computing the absolute differences between the abscissas and between the ordinates comprises: computing an absolute difference between an abscissa and an ordinate of each relative coordinate pair and an abscissa and an ordinate of any one of the plurality of sample coordinate pairs, the relative coordinate pair and the plurality of sample coordinate pairs both corresponding to a same part of the ear, the absolute difference between abscissas being recorded as a first absolute value and the absolute difference between ordinates as a second absolute value.

16. The method according to claim 5 , wherein a magnitude of the first predetermined value is set depending on application, comprising: if a fast matching speed is required, a relatively small first predetermined value is configured; and if a high matching accuracy is required, a relatively great first predetermined value is configured.

17. The mobile terminal according to claim 9 , wherein the touch screen is a piezoelectric touch screen.

18. The mobile terminal according to the claim 17 , wherein the piezoelectric touch screen employs piezoelectric multi-touch technology and high-precision analog-to-digital converters (ADCs) to analyze variation of strength of voltage or current at the each contact point to obtain the corresponding pressure value and coordinate pairs.

19. The mobile terminal according to claim 11 , wherein each part of the ear of the authorized user corresponds to a plurality of sample coordinate pairs, and the DSP unit computing the absolute differences between the abscissas and between the ordinates comprises: computing, by the DSP unit, an absolute difference between an abscissa and an ordinate of each relative coordinate pair and an abscissa and an ordinate of any one of the plurality of sample coordinate pairs, the relative coordinate pair and the plurality of sample coordinate pairs both corresponding to a same part of the ear, the absolute difference of the abscissas being recorded as a first absolute value and the absolute difference of the ordinates being recorded as a second absolute value.

20. The mobile terminal according to claim 10 , wherein a magnitude of the first predetermined value is set depending on application, comprising: if a fast matching speed is required, a relatively small first predetermined value is configured; and if a high matching accuracy is required, a relatively great first predetermined value is configured.